This invention relates to compositions for inhibiting angiogenesis and tumor growth. More particularly, the invention relates to compositions that bind to integrin xcex1vxcex23 and block the interaction of integrin xcex1vxcex23 with matrix metalloproteinase 2 (MMP2). The invention also relates to methods of inhibiting angiogenesis and tumor growth utilizing selective inhibitors of the binding of integrin xcex1vxcex23 with MMP2.
Invasion of vascular cells into tissues requires the coordinated interplay of numerous factors including proteinases, which remodel the extracellular matrix architecture, as well as cell adhesion molecules that recognize this provisional matrix. Recent reports have implicated that the 72 kDa matrix metalloproteinase 2 (MMP2) is a key player in vascular development and angiogenesis. For example, Kitoh et al. (J. Cell Sci., 109, 953-8 (1996)) report that MMP2 and its activator membrane type 1-matrix metalloproteinase (MT1-MMP) are coordinately expressed by mesenchymal cells almost exclusively during embryonic development, indicating specific matrix remodeling constraints in these tissues. In addition, angiogenesis and corresponding tumor growth are reduced in MMP2 knockout mice (see Itoh et al., Cancer Res., 58 1048-51 (1998)). Interestingly, Saftor et al. (Proc. Natl. Acad. Sci. U.S.A., 89, 1557-61 (1992)) have shown that ligation of the integrin xcex1vxcex23, itself a known mediator of angiogenesis, induces MMP2 production, suggesting a coordinated interplay of these two molecules during the vascular remodeling associated with blood vessel formation (see also Bafetti et al., J. Biol. Chem., 273, 143-9 (1998)). In fact, direct interaction between MMP2 and integrin xcex1vxcex23 has been demonstrated by Brooks et al. (Cell, 85, 683-93 (1996)). The negative regulation of MMP2 during vascular invasion and maturation was later shown by Brooks et al. to be dependent upon expression of xcex1vxcex23 (Cell, 92, 391-400 (1998)).
Although inhibition of angiogenesis and concomitant suppression of tumor growth by natural as well as synthetic inhibitors of MMP""s, including MMP2, has been documented, the translation of such strategies into clinical modalities has met with limited success, primarily due to the deleterious side effects of such broad spectrum inhibitors. Since MMP function, in general, may be required for many processes in the adult organism, active site inhibition of enzymatic function is likely to have far reaching effects on various biological processes involving tissue remodeling, such as wound healing. In fact, it has been documented that therapies with broad spectrum MMP inhibitors in clinical studies of various cancer types cause severe side effects, including inflammatory tendinitis, polyarthritis, and muscoskeletal pain syndromes, which are dose limiting and often persist after discontinuation of therapy. Given the limited distribution of integrin xcex1vxcex23 in adult organisms, however, one would predict that targeting the interaction between MMP2 and xcex1vxcex23 to the areas of neovascularization or cellular invasion should correspondingly limit the effects of such treatment-related toxicities. Indeed, the recombinant non-catalytic carboxy-terminal hemopexin domain of MMP2 (PEX), which mediates MMP2 binding to integrin xcex1vxcex23, has shown antiangiogenic and antitumor activity in vivo. The potential utility of such a large protein fragment, but with attendant shortcomings (e.g. large scale production problems, FDA quality and safety control issues and antigenicity), suggested the need for a more practical solution to this problem.
There is a need therefore, for chemical compounds that selectively inhibit MMP activity at tumor growth sites with minimal inhibition of MMP in other regions of the body.
The present invention provides novel compounds useful as inhibitors of angiogenesis and tumor growth. The invention also provides a method for the inhibition of the interaction of MMP2 with integrin xcex1vxcex23 and a method for inhibition of angiogenesis in cells containing integrin xcex1vxcex23. Further, the invention provides a method for inhibition of tumor growth by administration of MMP2-xcex1vxcex23 interaction inhibitors.
The compounds of the present invention are represented by Formula (I) and include glycyl lysine derivatives chemically attached to a linking group: 
wherein G1 and G2 are each independently xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94R1, xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)vxe2x80x94(C6H4)xe2x80x94X1, xe2x80x94NHxe2x80x94C(O)xe2x80x94NHxe2x80x94(CH2)vxe2x80x94(C6H4)xe2x80x94X1, xe2x80x94Oxe2x80x94C(O)xe2x80x94NHxe2x80x94(CH2)vxe2x80x94(C6H4)xe2x80x94X1, xe2x80x94Oxe2x80x94C(O)xe2x80x94Oxe2x80x94(CH2)vxe2x80x94(C6H4)xe2x80x94X1, or xe2x80x94NHxe2x80x94C(O)xe2x80x94CH2xe2x80x94(C6H4)xe2x80x94X1; Y1 and Y2 are each independently OH, C1-C4 alkyl, C1-C4 hydroxyalkyl, C1-C4 alkoxy, phenyl, benzyl, or xe2x80x94NH2; R1 is C1-C4 alkyl; X1 is halo, nitro, C1-C4 alkyl, C1-C4 alkoxy, or C1-C4 perfluoroalkyl; Z is xe2x80x94Cxe2x89xa1Cxe2x80x94, xe2x80x94C6H4xe2x80x94, cis xe2x80x94CHxe2x95x90CHxe2x80x94, trans xe2x80x94CHxe2x95x90CHxe2x80x94, cis xe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94, trans xe2x80x94CH2xe2x80x94CHxe2x95x90CHxe2x80x94CH2xe2x80x94, 1,4-naphthyl, cis-1,3-cyclohexyl, trans-1,3-cyclohexyl, cis-1,4-cyclohexyl, or trans-1,4-cyclohexyl; A is H or a covalent bond; m and n are each independently an integer having a value of 0 or 1; t is an integer having a value of 0 or 1; and v is an integer having a value of 1 or 2; with provisos that when A is H, t is 0; when A is a covalent bond, t is 1; when m is 0, Y1 is C1-C4 hydroxyalkyl; and when n is 0, Y2 is C1-C4 hydroxyalkyl. These compounds bind to xcex1vxcex23 and inhibit the interaction of MMP2 with xcex1vxcex23.
Preferred compounds of structural Formula (I) are represented in structural Formula (II): 
wherein R2 and R3 are each independently H, C1-C4 alkyl, phenyl or benzyl; X2 and X3 are each independently halo, nitro, C1-C4 alkoxy, C1-C4 alkyl, or C1-C4 perfluoroalkyl; A is H or a covalent bond; and t is an integer having a value of 0 or 1; with the proviso that when A is H, t is 0 and when A is a covalent bond, t is 1. When A is a covalent bond and t is 1, the glycyl lysine derivative moieties may be attached to the benzene linking group in the ortho, meta or para position.
When compounds of Formulas (I) and (II) are administered to cells containing xcex1vxcex23, the binding of xcex1vxcex23 with MMP2 is inhibited, thus interfering with an essential mechanism in angiogenesis. Interference with angiogenesis can also inhibit tumor growth by preventing vascularization of the tumor, thus starving it of nutrition. The angiogenesis and tumor growth inhibiting compounds of the present invention are thus useful therapeutic agents for the treatment of patients with tumors or angiogenic disorders. Because the present compounds bind to xcex1vxcex23, these compounds can also be used to suppress inflammatory events.
The compounds of the present invention may be formulated in suitable pharmaceutically acceptable media to afford pharmaceutical compositions useful for the treatment of tumors and other disorders involving undesired angiogenesis.
In a method aspect of the present invention, pharmaceutical compositions containing the compounds of Formulas (I) and (II) are prepared by formulating the compound in a pharmaceutically acceptable matrix. The pharmaceutical compositions of the active compounds are administered to a patient with a tumor to reduce or eliminate tumor growth. The active compounds can be administered parenterally by injection or by gradual infusion over time, or by any other method suitable for the particular dosage form.